ClassMethods

Constants

Files

• lib/neo4j/active_node/labels.rb:77

Methods

#base_class

def base_class
  unless self < Neo4j::ActiveNode
    fail "#{name} doesn't belong in a hierarchy descending from ActiveNode"
  end

  if superclass == Object
    self
  else
    superclass.base_class
  end
end

#blank?

def empty?
  !self.all.exists?
end

#count

def count(distinct = nil)
  fail(Neo4j::InvalidParameterError, ':count accepts `distinct` or nil as a parameter') unless distinct.nil? || distinct == :distinct
  q = distinct.nil? ? 'n' : 'DISTINCT n'
  self.query_as(:n).return("count(#{q}) AS count").first.count
end

#delete_all

Deletes all nodes and connected relationships from Cypher.

def delete_all
  self.neo4j_session._query("MATCH (n:`#{mapped_label_name}`) OPTIONAL MATCH n-[r]-() DELETE n,r")
  self.neo4j_session._query("MATCH (n:`#{mapped_label_name}`) DELETE n")
end

#destroy_all

Returns each node to Ruby and calls destroy. Be careful, as this can be a very slow operation if you have many nodes. It will generate at least one database query per node in the database, more if callbacks require them.

def destroy_all
  all.each(&:destroy)
end

#empty?

def empty?
  !self.all.exists?
end

#exists?

def exists?(node_condition = nil)
  unless node_condition.is_a?(Integer) || node_condition.is_a?(Hash) || node_condition.nil?
    fail(Neo4j::InvalidParameterError, ':exists? only accepts ids or conditions')
  end
  query_start = exists_query_start(node_condition)
  start_q = query_start.respond_to?(:query_as) ? query_start.query_as(:n) : query_start
  start_q.return('COUNT(n) AS count').first.count > 0
end

#find

Returns the object with the specified neo4j id.

def find(id)
  map_id = proc { |object| object.respond_to?(:id) ? object.send(:id) : object }

  result = find_by_id_or_ids(map_id, id)

  fail RecordNotFound.new(
    "Couldn't find #{name} with '#{id_property_name}'=#{id}",
    name, id_property_name, id) if result.blank?
  result.tap { |r| find_callbacks!(r) }
end

#find_by

Finds the first record matching the specified conditions. There is no implied ordering so if order matters, you should specify it yourself.

def find_by(values)
  all.where(values).limit(1).query_as(:n).pluck(:n).first
end

#find_by!

Like find_by, except that if no record is found, raises a RecordNotFound error.

def find_by!(values)
  find_by(values) || fail(RecordNotFound, "#{self.query_as(:n).where(n: values).limit(1).to_cypher} returned no results")
end

#find_each

def find_each(options = {})
  self.query_as(:n).return(:n).find_each(:n, primary_key, options) do |batch|
    yield batch.n
  end
end

#find_in_batches

def find_in_batches(options = {})
  self.query_as(:n).return(:n).find_in_batches(:n, primary_key, options) do |batch|
    yield batch.map(&:n)
  end
end

#first

Returns the first node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.

def first
  self.query_as(:n).limit(1).order(n: primary_key).pluck(:n).first
end

#last

Returns the last node of this class, sorted by ID. Note that this may not be the first node created since Neo4j recycles IDs.

def last
  self.query_as(:n).limit(1).order(n: {primary_key => :desc}).pluck(:n).first
end

#length

def count(distinct = nil)
  fail(Neo4j::InvalidParameterError, ':count accepts `distinct` or nil as a parameter') unless distinct.nil? || distinct == :distinct
  q = distinct.nil? ? 'n' : 'DISTINCT n'
  self.query_as(:n).return("count(#{q}) AS count").first.count
end

#mapped_label

def mapped_label
  Neo4j::Label.create(mapped_label_name)
end

#mapped_label_name

def mapped_label_name
  @mapped_label_name || label_for_model
end

#mapped_label_names

def mapped_label_names
  self.ancestors.find_all { |a| a.respond_to?(:mapped_label_name) }.map { |a| a.mapped_label_name.to_sym }
end

#size

def count(distinct = nil)
  fail(Neo4j::InvalidParameterError, ':count accepts `distinct` or nil as a parameter') unless distinct.nil? || distinct == :distinct
  q = distinct.nil? ? 'n' : 'DISTINCT n'
  self.query_as(:n).return("count(#{q}) AS count").first.count
end